JPH10159905A - Viscous damper for rotary shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a viscous damper for rotary shafts, which can give the damping function for torsional vibration to a rotary shaft such as a crank shaft to actively control oscillating vibration, and which can improve the durability of a crank shaft member. SOLUTION: A damper-mass 5 into which a ring-like inertia body 4 is fitted so as to permit it to move in the direction A-A' of rotation, and in which a viscous fluid 6 is sealed and which is rotated together with the inertia body 4 and further moved in the axial direction B-B' of the rotary shaft 1, is provided in a damper case 3 which is formed so as to be connected in ring manner in the circumferential direction of the rotary shaft 1 and which is rotated together with the rotary shaft 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous damper for a rotary shaft for attenuating torsional vibration of a rotary shaft such as a crankshaft of a vehicle engine.

[0002]

2. Description of the Related Art In an engine such as an automobile, a rotating torque due to an explosion pressure acting on a piston of the engine is periodically applied to the crankshaft. The torsional vibration occurs. When the frequency of the fluctuating torque acting on the crankshaft matches the natural frequency of the crankshaft system, resonance occurs, and the vibration amplitude suddenly increases, causing damage to the crankshaft system.

When this torque fluctuation is transmitted to the drive system, it causes rattling noise of the transmission gears and muffled noise in the passenger compartment. Therefore, it is necessary to attenuate the torsional vibration in order to reduce noise. There is. In particular, with the recent increase in speed and output of diesel engines, large-sized diesel engines generate larger torque than gasoline engines, and the weight of the crankshaft increases and the natural frequency decreases. For this reason, there is a high risk that resonance in torsional vibration occurs within the normal rotation speed of the engine.

[0004] Therefore, the torsional damper used for the crankshaft is changed from a rubber damper having a small vibration damping ability to a viscous rubber damper to a viscous damper having a high vibration damping ability in order to enhance the durability of the crankshaft. It is changing.
For example, as shown in FIG. 4, this viscous damper is provided at the front end of the crankshaft 1 where the amplitude of the torsional vibration increases.
The prior art structure of this viscous damper is connected via a crank pulley 10, as shown in FIG. 3, in a damper case 3 having an annular chamber that rotates with the crankshaft 1. A relatively rotatable inertia body 4 is incorporated, and a viscous fluid 6 having a viscous resistance such as silicon oil is sealed therein. When torsional vibration occurs in the crankshaft 1, the crankshaft 1 is rotated by inertia force. Since a relative speed is generated between the inertial body 4 and the damper case 3, viscous resistance is generated by viscous friction of the viscous fluid 6 enclosed between the inertial body 4 and the damper case 3, thereby obtaining a damping force having a vibration damping effect. Since this damping force can be applied to the crankshaft 1 via the damper case 3, an effect of damping torsional vibration can be obtained.

[0005]

However, not only the torsional vibration in the rotational direction but also the vibration in the direction perpendicular to the rotational axis, that is, the direction of the arrow CC 'in FIG. The front end of the shaft 1 oscillates in the vertical direction CC ′ in FIG. 4, and the upper and lower parts of the viscous damper 2 ′ are rotated along the BB ′ direction according to the oscillation. Vibrates in opposite phase.

[0006] When the swing vibration increases, the noise also increases. Therefore, it is necessary to reduce the swing vibration in order to reduce the vibration and noise in the vehicle. There is no effect of damping the swing vibration. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to add a torsional vibration damping function to a rotating shaft such as a crankshaft. It is another object of the present invention to provide a viscous damper for a rotating shaft that can also suppress vibration and improve durability of a crankshaft member.

[0007]

According to the present invention, there is provided a viscous damper for a rotary shaft according to the present invention, which is formed in a ring shape in a circumferential direction of the rotary shaft, and rotates together with the rotary shaft. Into the case, a ring-shaped inertial body is fitted so as to allow movement in the rotation direction, a viscous fluid is sealed, and furthermore, it rotates together with the inertial body, and is movable in the axial direction of the rotating shaft. It is provided with a damper mass.

The width of the damper mass in the axial direction of the rotation shaft is formed smaller than the width of the inertial body. This can prevent an increase in the axial width of the viscous damper for a rotating shaft. Further, the inertial body is provided with a plurality of through holes distributed in the circumferential direction, and the damper mass penetrates and is arranged.

In addition, by providing a fluid passage having an orifice while substantially penetrating the damper mass in the axial direction, by changing the orifice diameter and the like,
Since the damping force can be adjusted by changing the viscous resistance, it is easy to optimize the effect of the viscous damper.

[0010]

Embodiments of the present invention will now be described with reference to the drawings. As shown in FIG. 1, the viscous damper of the present invention has a ring-shaped or donut-shaped hollow communicating with the outer periphery of a disk-shaped damper plate 13 rotating with the rotating shaft 1 in the circumferential direction of the rotating shaft 1. A damper case 3 is provided, and a ring-shaped inertial body 4 called inertia ring is incorporated in the damper case 3 via a bearing metal 9 so as to be able to move or revolve. A viscous fluid 6 such as silicone oil capable of generating a resistance is sealed therein,
The damping action by viscous friction is caused to occur.

As shown in FIG. 1, through holes 7 penetrating substantially in the axial direction BB ′ of the rotating shaft 1 are provided in the ring-shaped inertial body 4 so as to be dispersed in the circumferential direction. ,further,
A bearing metal 9 ′ is fitted into the through hole 7, and a cylindrical damper mass 5 penetrates the bearing metal 9 ′, and is disposed so as to be movable substantially in the axial direction BB ′ of the rotating shaft 1. Such a damper mass 5 moves in accordance with the inertial force and performs relative motion with the inertial body 4 when the rotating shaft 1 swings and vibrates, so that an axial damping force is generated by the fluid friction of the viscous fluid 6. Can be done.

In order for the damper mass 5 to be able to make a relative movement between the damper mass 5 and the inertial body 4, the axial direction B
It is necessary to provide a movable gap at −B ′, but this may be formed to be smaller than the thickness of the inertial body 4 in consideration of the range of movement of the damper mass 5. Also, from the relation of the natural frequency of the crankshaft 1 system regarding the swinging vibration and the torsional vibration, when it is desired to increase the mass of each damper mass 5, the cross-sectional area should be increased or the shape should be changed, for example, in the circumferential direction. It is also possible to increase the mass by forming an elliptical shape having Further, the side surface of the damper case 4 may be formed in a convex shape protruding outward to provide a gap for movement in the axial direction B─B ′, and the thickness of the damper mass 5 may be increased by that amount.

Further, all or a part of the damper mass 5
And penetrates substantially in the direction of the rotation axis BB ′, and the orifice
By providing the fluid passage 8 having 14, the fluid resistance can be finely adjusted and the damping force can be adjusted. Then, as shown in FIG. 4, the viscous damper 2 is inserted through a mounting hole 11 provided in a damper plate 13 and fixed to the crank pulley 10, so that It is fixed to a crankshaft 1 which is a rotating shaft.

As described above, the embodiment of the present invention is shown in FIG.
However, the present invention is not limited to this. For example, as shown in FIG.
The annular damper mass 5 is circumferentially divided and fitted into the concave portions 7a on both sides, and these are connected by connecting rods. The connecting rods are inserted into the through holes 7 provided in the inertial body 4. Alternatively, it may be supported movably in the axial direction.

Further, as shown in FIG.
A concave portion 7a is formed on one side of the damper mass 5. A damper mass 5 is fitted into the concave portion 7a, and a guide 5a provided on the damper mass 5 is formed.
May be inserted into the through-hole 7 provided in the inertial body 4 and supported so as to be movable in the axial direction. Further, as shown in FIG. 2C, through-holes 7 having a semicircular cross section are dispersedly arranged on the outer peripheral portion of the inertial body 4, and
The damper mass 5 having a semicircular cross section may be held.

In short, the inertial body 4 engages with the inertial body 4 and rotates with the inertial body 4 in the viscous damper such as in the inertial body 4, between the inertial body 4 and the damper case 3, or in the damper case 3, and What is necessary is just to provide the damper mass 5 which can move substantially in the axial direction BB ′ of the rotating shaft 1. Although the number of the damper masses 5 is eight in FIG. 1, it is not necessary to limit the number to eight, and any number may be used, and the individual masses of the damper masses 5 need not be the same. From the viewpoint of optimizing the damping effect, it is preferable to provide a pair of damper masses 5 having the same mass at point-symmetric positions with respect to the axis 2c of the viscous damper 2.

With the above-described structure, the inertial body 4 and the damper mass 5 rotating therewith exhibit a damping effect against the torsional vibration of the crankshaft 1 as in the prior art. That is, when torsional vibration occurs, relative motion occurs between the inertial body 4 and the damper mass 5 rotating by the inertial force and the damper case 3 fixed to the crankshaft 1. Viscous resistance is generated by viscous friction of the viscous fluid 6 applied, and a damping force as a vibration damping action is applied to the crankshaft 1 via the damper case 3, so that torsional vibration can be reduced.

With respect to the swing vibration of the crankshaft 1, the damper masses 5 reciprocate independently in the axial direction BB 'of the rotary shaft 1, that is, the damper masses 5 are positioned above the drawing. When the damper mass 5 moves from B to B ′, the damper mass 5 located below moves in the B direction from B ′, thereby generating a viscous resistance force that attenuates swing vibration. Can be obtained. At this time, since the damper mass 5 is rotatable in the rotation direction and also movable in the axial direction, it functions as a mass in both directions and exhibits a damping effect in both directions.

Also, by changing the number or mass of the damper mass 5, the natural frequency of the viscous damper with respect to the swing vibration can be changed, and the shape of the damper mass 5 and the through hole 7 can be changed, for example, from a cylinder to a polygonal cylinder. The viscous fluid 6 is generated by changing the shape of the both ends of the damper mass 5 from a flat surface to a conical shape, a hemispherical convex shape, or a concave shape, for example. Since the magnitude of the viscous resistance to be changed can be changed, the viscous damper 2 that can obtain the optimal damping effect according to the vibration state of the engine can be configured.

Further, as shown in FIG.
By forming one or a plurality of fluid passages 8 having an orifice 14 and penetrating substantially in the direction of the rotation axis BB ′ inside the inside of the inside, the number of the fluid passages 8 or the diameter of the orifice 14 is changed. Since the viscous resistance generated by the viscous fluid 6 can be adjusted, the damping effect can be optimized also by this.

Accordingly, since the torsional vibration and the swinging vibration of the crankshaft 1 can be suppressed simultaneously by one viscous damper 2, the vibration of each member connected to the crankshaft 1, such as the viscous damper 2 and the crank pulley 10, is also reduced. it can. Therefore, the vibration stress of each member can be reduced, and the durability of each member can be improved. Also, engine vibration and noise caused by these vibrations can be reduced.

[0022]

According to the present invention, torsional vibration and swinging vibration of a rotating shaft such as a crankshaft can be suppressed by one viscous damper, so that vibration stress generated in a rotating shaft member can be reduced, and the viscous damper can be reduced. It is possible to improve the durability performance of the rotating shaft-based member, and reduce the noise caused by these vibrations.

[Brief description of the drawings]

FIG. 1 is a structural view showing a viscous damper according to an embodiment of the present invention, (a) is a partial sectional view of the front, and (b)
Is a side sectional view.

FIG. 2 is a partial structural view showing a through hole and a damper mass according to another embodiment of the present invention, where (a) is an example of a double-sided concave portion, (b) is an example of a single-sided concave portion, c) is a semi-circular example.

FIG. 3 is a structural diagram showing a conventional viscous damper;
(A) is a partial sectional view of the front, and (b) is a side sectional view.

FIG. 4 is a side view showing an assembled state of a viscous damper.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotary shaft (crankshaft) 2, 2 '... Viscous damper 3 ... Damper case 4 ... Inertial body (inertia) 5 ... Damper mass 6 ... Viscous fluid (silicone oil) 7 ... Through-hole 8 ... Flow passage 9.9 '… Bearing metal 10… Crank pulley 11… Mounting hole 12… Mounting bolt 13… Damper plate 14… Orifice AA ′… Rotation direction BB ′… Axial direction CC ′… Vertical direction (swinging direction)

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Naoki Ishikawa 3-25-1, Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture, Isuzu Motors Corporation Kawasaki Plant

Claims (4)

[Claims] 1. A ring-shaped inertia body (4) is provided in a damper case (3) formed in a ring shape in the circumferential direction of the rotating shaft (1) and rotating with the rotating shaft (1). The viscous fluid (6) is sealed while allowing it to move in the rotational direction (AA ′), and the inertial body (4)
And the axial direction of the rotation shaft (1) (B-
B ′) is a viscous damper for a rotating shaft, which is provided with a movable damper mass (5). 2. The viscous damper for a rotating shaft according to claim 1, wherein a width of the damper mass in the axial direction (BB ′) of the rotating shaft is smaller than a width of the inertial body. 3. The rotating shaft according to claim 1, wherein a plurality of through holes (7) distributed in a circumferential direction are provided in the inertial body (4), and the damper mass (5) penetrates the inertial body (4). Viscous damper. 4. The damper mass (5) is provided with a fluid passage (8) substantially penetrating in the axial direction (BB ′) and having an orifice (14). The viscous damper for a rotary shaft according to any one of the above.